1. Field of the Invention
The present invention relates to a technology adapted to remotely control an information-processing apparatus.
2. Description of the Related Art
Technologies relating to remote-control systems adapted to remotely control an information-processing apparatus via a network have been available. For example, technology relating to an electronic-conference system has been available. The electronic-conference system is formed, as a system including an information-processing apparatus that is to be remotely controlled (hereinafter referred to as “an apparatus to be controlled”) and at least two information-processing apparatuses controlled by conferees, that is, users (hereinafter referred to as “remote-control apparatuses”) that are connected to one another via a network. The electronic-conference system allows showing an output screen produced by the apparatus to be controlled on a predetermined output apparatus, that is, a display including a large display, a projector, and so forth so that the users can join the conference and share information offered by the output apparatus by remotely control the apparatus to be controlled.
The remote-control systems including the above-described electronic-conference system may be, for example, NetMeeting offered by Microsoft Corporation, Virtual Network Computing (VNC) and Desktop On-Call that are offered by International Business Machines Corporation (IBM), and pcAnywhere offered by Symantec Corporation.
FIG. 6 is a block diagram illustrating the configuration of an example electronic-conference system. In FIG. 6, an apparatus to be controlled 61 is provided. An image of the details of data transmitted from the apparatus to be controlled 61 is produced on an output apparatus including a large display, a projector, and so forth. A plurality of remote-control apparatuses 62 are provided and connected to the apparatus to be controlled 61 via a communication network 63. A user remotely controls the apparatus to be controlled 61 by operating the remote-control apparatus 62.
In the remote-control systems including the above-described electronic-conference system, the resolution of a common screen produced by the output apparatus is not necessarily equivalent to that of a screen that is produced by the remote-control apparatus 62 and used for controlling the apparatus to be controlled 61 (hereinafter referred to as a “remote-control screen”). Therefore, the known remote-control systems linearly transform the coordinates shown on the remote-control screen produced by the remote-control apparatus 62 and remotely control the apparatus to be controlled 61 based on the transformed coordinates. The above-described linear transformation includes enlargement and/or reduction transformation, and translation transformation.
Remote control performed by using the linear transformation with the enlargement and/or reduction transformation, and the translation transformation is briefly described with reference to FIG. 8 which schematically shows the relationship between a display screen produced on a display unit such as a display and an output apparatus of the known remote-control apparatus 62, and that of the apparatus to be controlled 61.
In particular, FIG. 8 shows a display screen (display area) 81 of the remote-control apparatus 62. The display screen 81 shows a remote-control screen 82, that is, a screen used for controlling the apparatus to be controlled 61 and a cursor (the pointer of a pointing device) 83. In the remote-control screen 82, coordinates are linearly transformed so that the apparatus to be controlled 61 is remotely controlled.
The cursor 83 is moved according to an input event transmitted by an input unit including a mouse, a keyboard, and so forth, so as to specify or drag an icon shown on the screen, for example. The coordinates of the cursor 83 shown on the remote-control screen 82 are determined to be (x, y).
FIG. 8 also shows a display screen 84 of the apparatus to be controlled 61. The display screen 84 produces the images of processing performed by the apparatus to be controlled 61 based on communications performed between the apparatus to be controlled 61 and the remote-control apparatus 62, a response output, and so forth. FIG. 8 further shows a cursor 85 shown on the display screen 84. The coordinates of the cursor 85 shown on the display screen 84 are determined to be (x′, y′).
In the above-described system, the details of processing performed by the apparatus to be controlled 61 are shown on the remote-control screen 82 in synchronization with the display screen 84. Further, where the user inputs predetermined information on the remote-control screen 82, the input event is transmitted to the apparatus to be controlled 61 via the network and the apparatus to be controlled 61 updates the details of the display screen produced on the display screen 84 based on the transmitted input event. For example, where a character is transmitted via the keyboard and the cursor is moved by operating the mouse on the remote-control screen 82, the event is transmitted to the apparatus to be controlled 61 and the result of processing performed based on the event is shown on the remote-control screen 82 and the display screen 84.
In FIG. 8, the remote-control screen 82 satisfies the expressions 600≦x≦1400 and 200≦y≦800, and the display screen 84 satisfies the expressions 0≦x′≦1600 and 0≦y′≦1200. In that case, the linear transformation including the enlargement and/or reduction transformation is achieved by the translation by as much as (−600, −200) and double enlargement in the directions x and y.
On the other hand, a linear-transformation method using translation alone is also known. Namely, the remote-control screen 82 is associated with part of the display screen 84 and the controllable area thereof is scrolled by using a scroll bar or the like. Subsequently, the entire common screen (the display screen 84) becomes controllable. More specifically, the remote-control screen 82 and the scroll bar or the like are shown on the display screen 81, and the expression of the linear transformation is updated every time the scroll is performed so that the entire display screen 84 becomes controllable.
In the above-described remote-control system, the remote control is performed by moving the cursor onto the remote-control screen 82 and transmitting information. Further, other applications running on the remote-control apparatus 62 can be controlled by moving the cursor away from the remote-control screen 82 and transmitting information.
However, when the linear transformation includes the enlargement and/or reduction transformation, every point shown on the display screen 84 of the apparatus to be controlled 61 cannot be specified via the remote-control apparatus 62. For example, when the remote-control system has the configuration shown in FIG. 8, the event that the cursor 83 is moved by as much as (−1, −1) in the remote-control screen 82 corresponds to the event that the cursor 85 is moved by as much as (−2, −2) in the display screen 84. Therefore, if the cursor 85 is at the position corresponding to the coordinates (x′, y′) on the display screen 84, for example, the remote-control apparatus 62 cannot control and move the cursor 85 to the place corresponding to the coordinates (x′−1, y′−1).
The above-described problem becomes significant as the difference between the resolution of the remote-control screen 82 and that of the display screen 84 becomes larger. For example, it becomes impossible to specify a small point and/or a little button by performing remote control. Further, if a user draws an image by using the path of cursor movement, it becomes impossible for the user to draw a smooth line.
Further, according to the above-described method wherein the controllable area is scrolled by the scroll bar or the like so that the entire display screen 84 becomes controllable, an area that can be controlled at a time is limited to the part shown on the remote-control screen 82. Therefore, a scrolling operation is required for controlling a part not shown on the remote-control screen 82, which places a burden upon the user. The above-described problem becomes more significant as the difference between the resolution of the remote-control screen 82 and that of the display screen 84 becomes larger.